1. Field of the Invention
The present invention relates to a method and apparatus of drilling holes and inspecting the same, and more particularly, to such an apparatus and method for determining the accuracy of drilled holes in a robotic-type assembly.
2. Background Art
It is common in the aircraft industry and other industries to drill a plurality of holes through workpieces which are to be joined to one another. Quite commonly, this is accomplished by placing a locating jig over the workpiece into which the holes are to be drilled, with the locating jig having a plurality of tapered locating holes. The drill assembly is commonly be made up of a drill housing which can be moved vertically into engagement with the locating jig. More specifically, the drill assembly has a housing with a tapered locating cone that comes into locating engagement with the locating holes in the jig. Then the drill itself is moved downwardly from the housing into engagement with the underlying workpiece to drill the hole through the workpiece.
It is of course necessary to inspect the holes to insure that these are drilled accurately to the proper diameter within certain tolerances so that these will properly receive the fastener to form the desired connection. Quite commonly, the tolerance of these holes must be within a fraction of a thousandth of an inch. There are various quality control devices which can be used to measure the diameter of a drilled hole, and in some of the devices there is an inspecting probe having laterally movable elements which engage the surface defining the hole and sensing means connected therewith to provide a reading of the hole diameter.
In recent years, the use of robotics in the drilling and inspection of holes has been a subject of increasing study. One of the problems in such an automated drilling and testing system is having the components operating within reasonably close tolerances to accomplish these functions properly. There is generally a certain amount of flexibility and inaccuracies in robotic mechanisms, and this must be considered in the overall drilling and inspection process.
Thus, there exists a need for a simple, robust, and accurate method and apparatus to gauge a hole diameter in the environment described above, and also to provide an effective drilling and inspecting apparatus and method for use in such a robotic environment.